Vehicle connectivity can be considered as an emerging technology that provides dissemination of warning messages and traffic information to vehicles running on the road. The deployment of vehicular ad-hoc network communication is strictly dependent on strictly on their security and privacy features. Recent advances in the hardware and software technology, tremendous improvements are made. Emerging Vehicular Ad-hoc Networks have the potential to improve the safety, traffic efficiency and as well as comfort to both drivers and passengers of highways. In the last three decades, various kinds of improvements are made in Wireless Ad-hoc Network and now a day's one of the most attractive research topic is Vehicular Ad-hoc Network (VANET) and become the most relevant form of Mobile Ad-hoc Networks. In this paper we address the Security in Vehicular ad-hoc Network. We provide a detail threat analysis as well as devise the solution of these threats. We provide a set of security protocols to protect the privacy and analyze the robustness and efficiency. In this paper we propose security architecture for vehicle communication. The architecture contains symmetric and asymmetric cryptography mechanism in the vehicular distributed environment for dissemination of information securely and efficiently. This paper contains Digital Envelop mechanism in a Distributed Environment for dissemination of message as well as Key Management that provide the privacy and security. [1, 2]. Upcoming Traffic safety initiatives rely heavily on information technology, which means that vehicles must be able to authenticate themselves and be traceable whenever necessary for law enforcement (detection of speed vehicles), crash reconstruction or toll collection. [3]